Abstract 3968: Eloquence Of Region And Extent Of Brain Ischemia Detected By DWI Predicts Degree Of 24h Nihss Score Improvement After Arterial Recanalization In Ischemic Stroke

Abstract

Introduction Improvement in NIHSS score at 24 hrs or delta NIHSS change (ΔNIHSS) is an early measure of response to recanalization treatment and has been associated with good outcome. We hypothesized that ΔNIHSS achieved with arterial recanalization may be influenced by eloquence of region involved within a vascular territory on baseline imaging. Methods Patients from prospectively collected Keimyung University stroke database, [2005-2009] were analyzed. Patients with proximal anterior circulation occlusions (ICA, MCA M1, proximal M2) who recanalized after IV tPA/IV tPA+endovascular therapy (TIMI 2/3) on DSA / MRA were included for final analysis.Detailed clinical and biochemical data collected prospectively was analyzed. Imaging analysis was done in University of Calgary. Two readers evaluated baseline DWI imaging and graded ischemic infarcts in16 anatomical regions(cortical MCA-M1,M2,M3,M4,M5,M6, insula; subcortical MCA- corona radiata -C1,C2,C3, basal ganglia; posterior limb of internal capsule; ACA- A1,A2 and PCA-P1,P2). Depending on the number of infarct regions involved, patients were categorized into three groups: mild - (0-3 infarct regions), moderate-(4-6), large and extensive (7-16). Improvement of 10 point in NIHSS score was labeled as treatment responders. ΔNIHSS change per point was the primary outcome. Results Among 265 patients in database, 101 patients who recanalized (TIMI2/3,) were analyzed. ΔNIHSS ≥10 was seen in 24 (24%) of subjects. There were 56% males. The mean age of patients was 65+-11.2yrs, Baseline median NIHSS was: 14 (IQR -11-16) and 24 hrs median NIHSS was 7 (IQR 6-9). There was no neurological improvement (ΔNIHSS) in patients with greater than 6 areas of involvement (p<0.001).Glucose was significantly higher in patients without ΔNIHSS compared to patients with ΔNIHSS (p=0.01). The most eloquent regions as measured by absence of delta NIHSS>10 despite recanalization were basal ganglia (OR 0.03 95%CI 0.004-0.25, p=0.001),posterior limb of internal capsule (OR 0.10 95%CI 0.01-0.85, p<0.001) ,M2 ( OR 0.06 95%CI 0.01-0.25, p<0.001)and C2 (core of corona radiata)(OR 0.12 95%CI 0.04-0.35 p<0.001). Conclusions ΔNIHSS at 24 hours after recanalization is high in a situation when more anatomical regions are involved. Patients with more than six infarcted regions had no improvement in ΔNIHSS. Patients with baseline involvement (ischemic core) of the corona radiata (C2), M2 (temporal lobe), basal ganglia and internal capsule have the least chance for significant ΔNIHSS improvement.